With regard to the conventional electronic device, an electromagnetic wave as an interference wave may leak out from, for example, an electronic component and wiring pattern mounted on a printed circuit board and hence affects an external electronic device.
Accordingly, for the conventional electronic device, the electromagnetic wave emitted from the printed circuit board can be absorbed by arranging an electromagnetic wave absorbing sheet around the printed circuit board and connecting the ground pattern of the printed circuit board to a metal plate, which encloses a casing and the inner surface of the casing (for example, see Patent Literature 1).
In other words, the radiation noise above a regulated level can be prevented from leaking out from the electronic device by absorbing the electromagnetic wave emitted from the printed circuit board through the electromagnetic absorbing sheet or the casing.